xv is an interactive image manipulation package for X11.
Tavis Ormandy of the Gentoo Linux Security Audit Team identified a flaw in the handling of image filenames by xv.
Successful exploitation would require a victim to process a specially crafted image with a malformed filename, potentially resulting in the execution of arbitrary code.
There is no known workaround at this time.
All xv users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-gfx/xv-3.10a-r10"